People have been asking whether Lorenzo Carcaterra's popular book about the crafty vengeance wreaked by four former inmates of a boys' correctional facility against their sexually abusive guards is fact or fiction. Carcaterra claims "Sleepers" is a true story. The movie version begins with a similar claim.

Carcaterra's book describes four childhood friends and fellow altar boys who grew up in New York's Hell's Kitchen of the 1960s, a dingy and dangerous working class neighborhood. At 13, the boys were as devoted to their priest, Father Bobby (Robert De Niro) - a former hood turned man of God - as they were to the local mafioso King Benny (the charming Vittorio Gassman), a benevolent dictator who gave them jobs as bagmen.

Despite Father Bobby's efforts to keep them straight, Lorenzo, Michael, Tommy and John - played by Joe Perrino, Brad Renfro, Geoff Wigdor and Jonathan Tucker - were sentenced to a hitch at the Wilkinson Home for Boys, a correctional facility, where they were sexually abused and tortured by a band of guards. The worst of them is Nokes, who is played by Kevin Bacon at his wicked best.

Around 13 years later, Tommy (Billy Crudup) and John (Ron Eldard), now neighborhood hitmen and drug abusers, run into Nokes in a bar. Without blinking, they shoot him dead. And after Bacon's performance as a cruel guard, you probably won't blink either.

Michael (Brad Pitt, with a strange haircut and a believable New York accent) has become an assistant district attorney and arranges to take the case in order to orchestrate his friends' acquittal. He does this with the help of Lorenzo (Jason Patric), now an aspiring writer doing clerical work at the Daily News, and King Benny, who still has plenty of tricks up his sleeves. Benny hires, or rather orders, Danny Snyder (Dustin Hoffman), a broken-down drunk of a defense lawyer to take the case. The reluctant Snyder will be provided with notes prepared by Michael. Michael carefully sets out to lose what the D.A.'s office considers an open-and-shut case.

But this is fine with him; he's been planning revenge for years and to that end has collected dossiers on all the offending guards. He views Nokes' messy death as the first step in getting even.

As directed by Barry Levinson, who also wrote the script, the movie is often compelling, but just as often, labored. In what amounts to a three-part saga - Innocent Youth, Incarceration and Terror, and Revenge - Levinson rarely curtails a tendency to say everything a little too thoroughly. But this is a well-crafted movie made by a pro who knows how to get good performances out of his strong cast. Levinson's real weakness is a tendency to lean toward sentimentality when the going gets tough, for instance, when he has to come up with an ending.

Lorenzo's narration is a bit confusing. He seems both omniscient and hopelessly subjective. At the end of the movie, when he tells us what became of all the key characters, he conspicuously omits himself. "I became a novelist but claimed I was writing non-fiction and made a lot of dough in Hollywood," is what you expect him to say.

More difficult to process is the fact that Lorenzo presents Tommy and John as the justified killers of Nokes, but also informs us that both of them murdered others before Nokes and would again after. Maybe Nokes got justice, but that doesn't make Tommy and John nice guys.

Frankly, I bought "Sleepers" right up until the Revenge section. So, Tommy and John are two ruined young men who can't forget the nightmare of their youthful incarceration. Getting even with Nokes never occurred to them before? Not according to this movie. Here, they just run into Nokes in a bar and, on the spot, go for payback. Why haven't they been looking for him for years? Couldn't they have arranged a somewhat less public comeuppance?

OK, maybe not. But what judge would allow a prosecutor to call a "character witness" for a murder victim, a man whose character was in no way in question until Michael introduced it as an issue. Of course, for Michael's secret goal, the issue of Nokes' character is crucial. And most important, without this witness, the movie would come to a grinding halt.

The character witness is one of Nokes' fellow torturers, who has no idea that his past is going to be discussed on the stand. Once Snyder begins a cross-examination with the obvious intention of obtaining a confession of rape and torture from the man, any judge paying attention would not have allowed the painstaking testimony to continue. Say Snyder could prove that Nokes was not a nice guy. What would that mean, that he deserved to die? Case dismissed?

The implausibility of this story is high, but it still retains the vibrance and interest of all good prison and courtroom dramas. And owing to the good taste and thoughtfulness of Levinson, the torture and sexual abuse are suggested rather than graphically described.

De Niro plays the same part he played in his own film, "A Bronx Tale." He's the role model, the guy from the neighborhood who knows right from wrong and wants to teach it to the kids.

Sometimes the movie lacks a quietness, an omission most egregiously felt at the end. Lorenzo narrates himself into a ridiculous corner, muttering about "The future lay sparkling ahead and we thought we'd know each other forever." At times like this you might find yourself wondering why Bacon has a Philadelphia accent.

But, fortunately, Gassman's ease and elegance diverts one's attentions from such distractions. Lorenzo says to King Benny, who is spreading bird feed in the park, "I didn't know you like pigeons so much." Benny looks as if he can't begin to explain. He says, "I like anything that don't talk." And you know exactly what he means.